A New York court has rejected a lawsuit challenging the New York State Department of Environmental Conservation’s (NYSDEC) renewal of the Caithness Long Island Energy Center’s (CLI Facility) Title V air permit as purportedly violating the Climate Leadership and Community Protection Act (CLCPA) – the first decision on a CLCPA-based challenge to NYSDEC’s renewal of an air permit.
The judgment by the New York State Supreme Court for Nassau County (Hon. Maureen McHugh Heitner) is a significant victory for clean and efficient gas-fired power plants like the CLI Facility, which supplies nearly 11% of Long Island’s electricity. Such plants are critical to maintaining stable and reliable electricity while New York expands its renewable energy resources.
In Sierra Club v. NYSDEC, the petitioners commenced a CPLR Article 78 proceeding against NYSDEC and Harris Beach Murtha client Caithness Long Island LLC (Caithness), which owns and operates the 346-megawatt gas-fired CLI Facility in Suffolk County.
Like all operators of gas-fired electric generating facilities in New York, Caithness requires a permit issued under Title V of the federal Clean Air Act. Title V permits have a five-year term and must be renewed periodically. Caithness applied to renew the CLI Facility’s Title V permit in 2016. While that renewal application was pending, New York enacted the CLCPA in 2019.
Complying with the CLCPA
Broadly, the CLCPA established statewide goals to reduce greenhouse gas (GHG) emissions between 2019 and 2050 in all sectors of New York’s economy and created a Climate Action Council to develop a scoping plan and recommend specific regulatory measures to achieve those GHG reductions goals. As relevant here, Sections 7(2) and (3) of the CLCPA require that, when issuing permits, licenses and other administrative approvals, state agencies “consider whether such decisions are inconsistent with or will interfere with the attainment of the statewide greenhouse gas emission [GHG] emission limits” or “would disproportionately impact disadvantaged communities.”NYSDEC subsequently issued guidance explaining how it would exercise the broad discretion granted to it by the CLCPA.
NYSDEC issued the final renewal of Caithness’s Title V permit in September 2024 and specifically stated that renewal of the permit was not inconsistent with the CLCPA because it would not increase the CLI Facility’s GHG emissions. Sierra Club sued to invalidate the permit, asserting that NYSDEC had improperly “grandfathered” or “exempted” permit renewals that do not increase GHG emissions from the requirements of the CLCPA.
However, the administrative record demonstrated that NYSDEC complied with both Sections 7(2) and (3) of the CLCPA by expressly considering whether renewal of Caithness’s Title V permit would be inconsistent with the statewide GHG emissions goals or disproportionately impact disadvantaged communities.
State’s Determination of Consistency with GHG Goals Was Enough
In a July 25, 2025, decision, Judge Heitner ruled in favor of Caithness and NYSDEC and denied the petition challenging renewal of the CLI Facility’s Title V permit. Relying on the text of CLCPA § 7(2), the court held that once NYSDEC determined that renewal of the CLI Facility’s permit was not inconsistent with the statewide GHG emissions goals, NYSDEC was not required to provide further “justification” for its decision or identify alternatives or GHG mitigation measures.
The CLI Facility is the single most efficient and lowest-emitting gas-fired power plant on Long Island (and one of the most efficient/lowest-emitting facilities anywhere in the United States). The court recognized that NYSDEC’s renewal of Caithness’s Title V permit is consistent with the CLCPA, which contemplates an incremental, responsible reduction in statewide GHG emissions over time, without compromising either the reliability of New York’s electrical grid or the competitiveness of New York businesses.
